Enable text-line-height, text-letter-spacing paint properties to format options

[tristen]

Motivation

I want to be able to adjust the line-height and letter-spacing of the smaller text "Saint Petersberg"

This becomes more important when two font families are used.

Design Alternatives

• Contend with spacing feeling off
• For line-height, there are less flexible alternatives like
  • Using an exaggerated line-height and increase the label max-width
  • Adding an additional line break (which limits control over height value)

Design

[
  "format",
  ["get", "name_ru"],
  {},
  "\n",
  {},
  ["get", "name_en"],
  {
    "font-scale": 0.75,
    "text-line-height": 0.2,
    "text-letter-spacing": 0.1
  }
]